FIELD SURVER OF ICE JAM IN MARCH 2020 AND EVALUATION OF ICE JAM OCCURANCE RISK

Abstract

 As a damage reduction plan with the ice jam, we aim to develop practical ice jam occurrence prediction model. It is important to collect examples of recent ice jams and to solve the problems by applying the model on actual rivers for practical use. At first we investigated the mechanism of ice jam which occurred in several rivers in Hokkaido in March 2020. Time of outbreak and disappearance of ice jam was obtained successfully with video image by river surveillance camera and telemeting water level. Next we tried to evaluate the occurance risk evaluation of this ice jam. We compared with factor which influenced ice jam occurance in 2018 and in 2020. We also examined problems and improvement about outbreak prediction with the river ice thickness prediction model.